The AM3715 OHCI controller will not function without the EHCI unit's 120m fclk being enabled. If all the ports in the system are set to OHCI then the 120m_fclk will not get enabled and no devices are detected. Add a new (optional) property to signal the system must enable the 120m_fck for OHCI so that if no EHCI ports are signalled then the 120m_fclk should be enabled. We have found no information about why this is necessary, but it is suspected the EHCI controller does not complete the initial reset sequence and therefore does not hand control of the USB port back. Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx> --- Documentation/devicetree/bindings/usb/omap-usb.txt | 3 +++ drivers/mfd/omap-usb-host.c | 4 ++++ 2 files changed, 7 insertions(+) diff --git a/Documentation/devicetree/bindings/usb/omap-usb.txt b/Documentation/devicetree/bindings/usb/omap-usb.txt index 38d9bb8..fb5fea5 100644 --- a/Documentation/devicetree/bindings/usb/omap-usb.txt +++ b/Documentation/devicetree/bindings/usb/omap-usb.txt @@ -23,6 +23,9 @@ OMAP MUSB GLUE Optional properties: - ctrl-module : phandle of the control module this glue uses to write to mailbox + - ti,ohci-needs-120m-fck : bool, enable the 120m ehci clock even if just + using ohci. Needed for AM3517 in OHCI only mode. + SOC specific device node entry usb_otg_hs: usb_otg_hs@4a0ab000 { diff --git a/drivers/mfd/omap-usb-host.c b/drivers/mfd/omap-usb-host.c index 1d924d1..13880cf 100644 --- a/drivers/mfd/omap-usb-host.c +++ b/drivers/mfd/omap-usb-host.c @@ -680,6 +680,10 @@ static int usbhs_omap_probe(struct platform_device *pdev) need_logic_fck |= true; } + /* The AM3517 requries the 120m-fck active to allow the OHCI to work */ + if (of_property_read_bool(dev->of_node, "ti,ohci-needs-120m-fck")) + need_logic_fck |= true; + if (need_logic_fck) { omap->ehci_logic_fck = devm_clk_get(dev, "usbhost_120m_fck"); -- 2.6.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html